As there was no 64-bit version of Buster's Anti Delete DLL available, I've created a similar plugin called NoDelete, which is available for both 32 and 64-bit platforms. I've hooked API functions, which have the delete functionality that I know of:

It prevents programs running under Sandboxie to delete files - useful for example during installation of a program or when some malware creates temporary files, do something with them and then deletes them to hide it's activity. With this plugin the programs think they were successful when deleting files although in reality the files are left in the sandbox.

Of course this could cause a different response from the program if it checks if the file is really deleted, but that's a trade-off.